Climbing Stairs

Problem: Climbing Stairs

The number of solutions of climbing n stairs is actually decided by the solutions of climbing n-1 stairs and n-2 stairs.

Code in Python:

class Solution(object):
    def climbStairs(self, n):
        """
        :type n: int
        :rtype: int
        """
        dp = [1, 1]

        for i in xrange(2, n+1):
            dp.append(dp[i-2]+dp[i-1])
        return dp[n]